With his upset win in the Democratic primary, Democratic-Socialist Mamdani has the inside track in New York City’s mayoral race. New York already has a host of problems: crime, illegal immigration, high spending, high taxes, and a declining population and dwindling tax base. Mamdani’s radical policy proposals only threaten to add to these woes.

Free bus service, government-run grocery stores, and government-built housing all promise to increase New York City’s already high spending. Mamdani’s commitment to increase taxes on higher income and whiter neighborhoods will increase New York City’s already high taxes. Together, the two will squeeze the city’s economy, pushing out more of the city’s population and further eroding its tax base. Mamdani’s earlier support for defunding the police and not cooperating with ICE will hike crime and illegal immigration.

In sum, Mamdani threatens to accelerate the negative economic and societal spiral New York City has been experiencing for some time. It is the last thing New Yorkers need.

Accentuating America’s perception of Democrat excesses in the nation’s biggest city is also the last thing Democrats need. How big a problem is this for Democrats? Such topics were among President Biden’s worst polling performances: According to Real Clear Politics’ final average of Biden’s job approval polling, Americans gave him just a 38.8% approval on his handling of the economy, 38% on crime, and 33.5% on immigration.

What’s more, Mamdani, and other big-city mayors and mayoral candidates espousing radical policies, could eclipse the Democrats’ national campaign strategy of running against Trump as well.

Over the last decade, Democrats’ only national election successes have come when Trump is the election’s focus. In 2018, with Trump in office, they won control of the House of Representatives. In 2020 with Trump as the incumbent, Democrats won the presidency and the Senate.

Conversely in 2016, Democrats could not escape Hillary Clinton being their standard-bearer. As a result, they lost the White House in a profound political upset. In 2022, with Joe Biden in office, Democrats lost the House. In 2024, Biden and Harris were both incumbents; with reelections being referendums on incumbents, the focus was again on Democrats, and they lost the presidency.

Having learned these lessons, Democrats aim to make Trump the focus in 2026 and 2028 — even without Trump on the ballot. Despite a string of policy successes, Trump remains a divisive political figure. According to RCP’s recent average of national polling, Trump’s job approval rating is just 45.9% and his favorability rating only 44.5%.

Without Trump on the 2026 and 2028 ballots, Republicans must defend his divisive legacy without having the benefit of his vote-getting ability.

More than a strategy, this is a necessity for Democrats. Trump is the only thing that unites them as a party. Democrats lack their own winning policies; their most prominent stands against Trump have been issues — illegal immigration, transgender rights, and crime — that cost them in November 2024. The result is that Democrats find themselves with an abysmal standing: A recent WSJ poll found only 33% of Americans had a favorable view of the Democratic Party.

If elected mayor of America’s largest city, Mamdani undermines this approach.

Republicans would love nothing better than to run against New York, the same way they ran against California when Kamala Harris became Democrats’ presidential nominee. Republicans proved last year that they can win the presidency handily without winning either coast.

In 2024, Republicans lost New York, California, Washington and Massachusetts by an average of 58% of the popular vote. Yet, Democrats won only 121 of the remaining 433 electoral votes — just 28%. Republicans won 72% of the electoral votes outside Democrats’ coastal strongholds. Only needing 270 total electoral votes for victory, Trump’s 312 votes give Republicans a virtual stranglehold on America’s “flyover” country — where 80% of America’s total electoral votes lie.

In contrast, Democrats have no chance without New York and California; so, they are stuck with sticking up for both. If Mamdani succeeds in rotting the Big Apple, Democrats could see 2026 and 2028 potentially going from a best-case scenario to a worst-case scenario. Democrats would find themselves either defending Mamdani’s radical policies and alienating America or rejecting Mamdani’s radicalism and alienating their far-left supporters.

(J.T. Young is the author of the recent book, “Unprecedented Assault: How Big Government Unleashed America’s Socialist Left,” and has more than three decades’ experience working in Congress, the Department of Treasury, the U.S. Office of Management and Budget and representing a Fortune 20 company.)